I have spend more than a day with Office installation problems and now I really need help.
I downloaded OfficeProfessionalPlus_x64_de-de  (Office 2013, 64 bit, German, trail) and tried to install.
My installed 32bit Single Image Office 2010 prevented the installation, so I uninstalled that.
But that wasn't enought, so I followed the instructions on https://support.office.com/en-gb/article/Uninstall-or-remove-Microsoft-Office-2010-suites-90635a1d-aec8-4653-b358-67e1b766fc4d to completely remove all files and clean the registry.
I followed the manual path, because FixIt-50450 reported a Windows-Installer-Error: a script couldn't be executed.
Next I installed Office 2013, but the activation by entering a product key didn't work.
I completely uninstalled it again. After that I also followed the manual instructions for Office 2010 given in above mentioned article. Where applicable, I substituted Office14 with Office15.
I reinstalled Office 2013 again on this now Office-free machine. Again, the activation using the product key didn't work.
Now I tried ospprearm, thinking perhaps I could skip the activation, but that returned error 0xc004fe00. Google yields that it means my Windows 7 would not be genuine.
Since it is, I headed to the control panel, system, to check. At first, I actually didn't display the activation status, but after a few seconds it changed to show the Windows product ID.
Perhaps that solved the error, so I tried the rearm again, but it still displayed 0xc004fe00, ever though this is a perfectly legal installation.
Then I entered cscript ospp.vbs /dstatus and received the information, that 'The Software Licensing Service reported that activation is required to recover from tampering of SL service trusted store. Last 5 characters of installed product: 27GXM'
So what am I supposed to do now, please help!

Hi,

Based on the description above, you have installed and uninstalled Office for a couple of times, this may cause the issue that the product key has been considered as used for more than once.

In this scenario, the first thing I suggest is to contact the customer service, ask them if your product key is still valid:

http://support.microsoft.com/gp/customer-service-phone-numbers/en-us

If you need further assistance, please feel free to post back.

Regards,

Melon Chen
TechNet Community Su

Hi Melon,

thank you for your answer. The key is valid, as I am able to install the software to a different machine using this trail key. The problem with my main computer seems to be that I may have tampered with the registry. In order to get rid of the previous installation of Office Single Image and of everything else Office-related prior to installing Office 2013, in an attempt to clean the computer completely from all office products, I deleted almost every register key containing 0FF1CE or Office, including Office Software Protection. That may have broken something.

However, if there is no quick fix or easy solution, I don't bother that much anymore, as I am going to switch to W10 soon. I already have an image with a working copy of O2013 running.